The rationale for integrated childhood meningoencephalitis by liaoqinmei

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									             Publication: Bulletin of the World Health Organization; Type: Lessons from the Field
                                      Article DOI: 10.2471/BLT.08.052951


The rationale for integrated childhood meningoencephalitis
surveillance: a case study from Cambodia
Sok Touch,a John Grundy,b Susan Hills,c Manju Rani,d Chham Samnang,e
Asheena Khalakdinaf & Julie Jacobsong
a
    Communicable Disease Control Department, Ministry of Health, Phnom Penh, Cambodia.
b
    Nossal Institute for Global Health, University of Melbourne, 187 Grattan Street, Melbourne, Vic., Australia.
c
    PATH, Seattle, WA, United States of America (USA).
d
 Expanded Programme on Immunization, World Health Organization Regional Office for the Western Pacific,
Manila, Philippines.
e
    PATH, Phnom Penh, Cambodia.
f
    PATH, Bangkok, Thailand.
g
    Bill & Melinda Gates Foundation, Seattle, WA, USA.
Correspondence to John Grundy (e-mail: jgrundy@unimelb.edu.au).
(Submitted: 11 March 2008 – Revised version received: 7 August 2008 – Accepted: 3 September 2008 – Published
online: 4 March 2009)
          Abstract
Problem Recent progress in vaccine availability and affordability has raised prospects for
reducing death and disability from neurological infections in children. In many Asian countries,
however, the epidemiology and public health burden of neurological diseases such as Japanese
encephalitis and bacterial meningitis are poorly understood.
       Approach A sentinel surveillance system for Japanese encephalitis was developed and
embedded within the routine meningoencephalitis syndromic surveillance system in Cambodia
in 2006. The sentinel surveillance system was designed so surveillance and laboratory testing
for other etiologies of neurological infection could be incorporated.
      Local setting The Communicable Disease Control department of the Ministry of Health
in Cambodia worked with partners to establish the sentinel surveillance system.
        Relevant changes The sentinel surveillance system has provided important information
on the disease burden of Japanese encephalitis in Cambodia and is now providing a platform
for expansion to incorporate laboratory testing for other vaccine-preventable neurological
infections in children.
      Lessons learned Sentinel surveillance systems, when linked to syndromic reporting
systems, can characterize the epidemiology of meningoencephalitis and identify the proportion
of hospital-based neurological infection in children that is vaccine preventable. Integrated
systems enable consistency in data collection, analysis and information dissemination, and they
enhance the capacity of public health managers to provide more credible and integrated
information to policy-makers. This will assist decision-making about the potential role of
immunization in reducing the incidence of childhood neurological infections.

Justification de la surveillance intégrée de la méningo-encéphalite
infantile : étude cas-témoin au Cambodge
Résumé



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         Publication: Bulletin of the World Health Organization; Type: Lessons from the Field
                                  Article DOI: 10.2471/BLT.08.052951
Problématique Les progrès récemment enregistrés en matière de disponibilité et d’accessibilité
économique des vaccins ont soulevé des espoirs de réduire la mortalité et l’incapacité dues aux
infections neurologiques chez l’enfant. Dans de nombreux pays asiatiques cependant, on
appréhende mal le poids épidémiologique et le fardeau pour la santé publique que représentent
les maladies neurologiques telles que l’encéphalite japonaise et la méningite bactérienne.
Démarche Un système de surveillance sentinelle pour l’encéphalite japonaise a été développé
et intégré au système de surveillance syndromique systématique de la méningo-encéphalite au
Cambodge en 2006. Le système de surveillance sentinelle a été conçu de manière à pouvoir
intégrer la surveillance et les analyses en laboratoire relatives à d’autres étiologies d’infection
neurologique.
Contexte local Le Département Lutte contre les maladies transmissibles du Ministère de la
santé cambodgien a collaboré avec ses partenaires pour mettre en place ce système de
surveillance sentinelle.
Modifications pertinentes Le système de surveillance sentinelle a fourni des informations
importantes sur la charge de morbidité due à l’encéphalite japonaise au Cambodge et offre
actuellement une plateforme de développement permettant l’intégration de tests de laboratoires
pour d’autres infections neurologiques infantiles évitables par la vaccination.
Enseignements tirés Lorsqu’il est couplé à un système de notification des syndromes, un
système de surveillance sentinelle peut caractériser l’épidémiologie de la méningo-encéphalite
et identifier la proportion d’infections neurologiques nosocomiales évitables par la vaccination
dans la population infantile. L’intégration de ces systèmes permet une plus grande cohérence
dans la collecte des données et dans l’analyse et la diffusion des informations et renforce la
capacité des gestionnaires de la santé publique à fournir des informations plus crédibles et plus
synthétiques aux décideurs politiques. Cela contribuera à la prise de décisions concernant le
rôle potentiel de la vaccination dans la réduction de l’incidence des infections neurologiques
chez l’enfant.

Justificación de la vigilancia integrada de la meningoencefalitis en
la niñez: estudio de casos en Camboya
Resumen
Problema Los recientes progresos en materia de disponibilidad y asequibilidad de las vacunas
han avivado las expectativas de reducir la mortalidad y las discapacidades por infecciones
neurológicas en los niños. En muchos países asiáticos, sin embargo, no se conocen lo
suficiente la epidemiología y la carga de salud pública de enfermedades neurológicas como la
encefalitis japonesa y las meningitis bacterianas.
Enfoque Se desarrolló un sistema de vigilancia centinela de la encefalitis japonesa, que pasó a
integrarse en el sistema de vigilancia sindrómica sistemática de la meningoencefalitis en
Camboya en 2006. El sistema de vigilancia centinela se diseñó de modo que pudiera incorporar
pruebas de vigilancia y de laboratorio para otras causas de infección neurológica.
Contexto local El departamento de Control de las Enfermedades Transmisibles del Ministerio
de Salud de Camboya colaboró con diversos asociados a fin de establecer el sistema de
vigilancia centinela.
Cambios destacables El sistema de vigilancia centinela ha facilitado información relevante
sobre la carga de morbilidad por encefalitis japonesa en Camboya y proporciona hoy una




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             Publication: Bulletin of the World Health Organization; Type: Lessons from the Field
                                      Article DOI: 10.2471/BLT.08.052951
plataforma de expansión que permite incorporar las pruebas de laboratorio necesarias para
otras infecciones neurológicas prevenibles mediante vacunación en la niñez.
Enseñanzas extraídas Si se vinculan a sistemas de notificación de síndromes, los sistemas de
vigilancia centinela permiten caracterizar la epidemiología de la meningoencefalitis y determinar
a nivel hospitalario la proporción de infecciones neurológicas prevenibles mediante vacunación
en la población infantil. Los sistemas integrados redundan en una mayor coherencia en la
recogida de datos, el análisis y la difusión de información, así como en una mayor capacidad
de los responsables de gestionar la salud pública para suministrar información más fiable e
integrada a las instancias normativas. De ese modo se facilita la adopción de decisiones sobre
la contribución potencial de la inmunización a la reducción de la incidencia de infecciones
neurológicas en la niñez.

                                                                                           ‫ط‬         ‫يجش‬
                       ‫ُ َ ِساد انتش ُذ انًتكبيم النتهبة انسحبَب وانذيبغ فٍ انطفىنخ: دساسخ حبنخ يٍ كًجىدَب‬
                                                                                                                                                      ‫يهخض‬
                                                                               ‫ّق‬                                                    ‫ذ‬       ‫د‬
   ‫المشكلة: نقذ أ َي انتق ُو انحبنٍ فٍ تىافش انهقبحبد وانقذسح عهً ششائهب إنً تى ُع اَخفبع انىفُبد وانعجض انُبجًٍُ عٍ انعذوي انعظجُخ نذي األطفبل. إال أٌ انفهى‬
  ‫الصال ّقبطشاً فٍ انعذَذ يٍ انجهذاٌ اِسُىَخ عٍ اإلحبطخ ثبنعتء انزٌ تُىء ثه انىثبئُبد وانظحخ انعًىيُخ ثسجت تهك األيشاع يثم انتهبة انذيبغ انُبثبٍَ وانتهبة‬
                                                                                                                                          .ٍ‫انسحبَب انجشثىي‬
‫. وّقذ‬                                                                   ‫ط‬                                                   ‫ط‬          ‫طى‬
           ‫األسلوب: نقذ ُ ِس َظبو تش ُذ خبفش النتهبة انذيبغ انُبثبٍَ وأديج ػًٍ َظبو انتش ُذ انشوتٍُُ انًتالصيٍ النتهبة انسحبَب وانذيبغ فٍ كًجىدَب فٍ عبو‬
                                                                                              ‫ط‬                ‫َي‬                       ‫ط‬           ً
                                       .‫ط ِى َظبو انتش ُذ انخبفش ثحُث ًَكٍ أٌ ُذْ َج ػًُه انتش ُذ وانفحىص انًختجشَخ نألسجبة اإليشاػُخ نهعذاوي انعظجُخ‬
                                           ‫ذ‬
                                     .‫الموقع المحلي: ّقسى يكبفحخ األيشاع انسبسَخ فٍ وصاسح انظحخ انكًجىدَخ، انزٌ عًم يع ششكبء نتأسُس َظبو تشط ٍ خبفش‬
                     ‫ب‬           ‫ذ‬                                                                                   ‫ط‬
   ‫التغيرات ذات العالقة: ّقذو َظبو انتش ُذ انخبفش يعهىيبد هبيخ حىل عتء أيشاع انتهبة انذيبغ انُبثبٍَ فٍ كًجىدَب، وهى َق ِو اٌِ يُطهقً نتىسُع ديج انفحىص‬
                                                                                .‫انًختجشَخ نهعذاوي انعظجُخ األخشي انتٍ ًَكٍ تىّقُهب ثبنهقبحبد نذي األطفبل‬
            ‫ش‬                                                          ‫ذ‬                                                ‫ط‬
  ‫الدروس المستفادة: ًَكٍ نُظى انتش ُذ انخبفش عُذ سثطهب ثُظى اإلثالغ انًتالصيٍ أٌ تق ِو وطفب نهخظبئض انىثبئُخ النتهبة انسحبَب وانذيبغ وأٌ تتع َف يٍ واّقع‬
                    ‫ك‬                                         ‫ّق‬
    ‫انًعهىيبد انًستًذح يٍ انًستشفُبد عهً انُسجخ انًئىَخ نهعذوي انعظجُخ ثٍُ األطفبل وانتٍ ًَكٍ تى ُِهب ثبنهقبحبد، حُث إٌ انُظى انًتكبيهخ تً ٍِ يٍ اتسبق جًع‬
                         ‫ال‬                                                                                ‫ض‬
‫انًعطُبد وتحهُم انًعهىيبد وَششهب، كًب أَهب تع ِص ّقذسح انقبئًٍُ عهً إداسح انظحخ انعًىيُخ عهً تقذَى يعهىيبد أكثش يىثىّقُخ وتكبي ً ألطحبة انقشاس انسُبسٍ؛‬
                                                                                                                                          ‫ت‬
                                                       .‫يًب َسبعذ عهً ا ِخبر انقشاساد حىل انذوس انًًكٍ نهتًُ ُع فٍ خفغ يعذالد انعذوي انعظجُخ فٍ انطفىنخ‬

Introduction
Neurological infection is an important cause of death and disability in children in Asia.1–4 Major vaccine-
preventable etiologies of meningoencephalitis (ME) in Asia include Japanese encephalitis (JE) virus and
bacteria such as Haemophilus influenzae type b (Hib), Neisseria meningitidis and Streptococcus
pneumoniae. Public health initiatives to control these diseases are becoming more feasible with improved
vaccine availability and affordability.5

          However, in many Asian countries, the epidemiology and public health burden of JE and bacterial
meningitis are poorly understood. Generation of disease-specific data for ME was spearheaded in some
countries by the establishment of vertical disease-specific initiatives for control of JE, Hib and
pneumococcal diseases (e.g. JE project at PATH, and the GAVI Alliance’s Hib Initiative and
pneumoADIP). However, the benefits of combining surveillance for meningitis and encephalitis are
evident in terms of case identification, simplified logistics and systems, and the potential for more
coordinated data analysis and consistent information to assist decision-makers in relation to vaccine
introduction programmes.



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          Publication: Bulletin of the World Health Organization; Type: Lessons from the Field
                                   Article DOI: 10.2471/BLT.08.052951
       This paper provides an example of development of an integrated ME surveillance system in
Cambodia and, on the basis of this case study, presents the rationale and challenges for design and
operation of such systems more generally in Asia.

System design for ME surveillance
A JE sentinel surveillance system was developed and embedded within the routine ME syndromic
surveillance system in Cambodia in 2006. The sentinel system was designed so that it could provide a
platform to incorporate laboratory testing for other central nervous system (CNS) infections in children.

       The goal of the ME surveillance system in Cambodia is to assess disease burden due to
neurological infection in children. Weekly reporting to the national level on the number of clinical
syndromic ME cases and deaths is required from all district and provincial hospitals across the country.
The syndromic ME surveillance is part of the national outbreak surveillance and response system.

       The JE sentinel surveillance system was incorporated within this system. Six hospitals were
chosen as sentinel sites from geographically diverse parts of the country. ME patients have
epidemiological data gathered at these sites. When cerebrospinal fluid and blood are collected for routine
case management, tubes are also collected for specific etiology testing. These additional samples are
transported weekly to the National Institute of Public Health laboratory in the capital, Phnom Penh.
Initially, only JE diagnostic testing by enzyme-linked immunosorbent assay (ELISA) was conducted. The
system has been expanded recently and testing for vaccine-preventable etiologies of bacterial meningitis
is now being added.

       In the first year of surveillance, 47 of 275 (17.1%) ME cases reported from six sentinel sites were
laboratory-confirmed as JE. The initial findings from the JE sentinel surveillance system are consistent
with results of several previous research studies that have indicated approximately 20–30% of all acute
encephalitis cases in Cambodia are attributable to JE virus infection.6,7 With this preliminary data, an
estimate of national ME incidence of 42.6 cases per 100 000 children aged less than 15 years and a
minimum JE incidence of 7.3 per 100 000 children aged less than 15 years were calculated. Although
many factors limit the precision of this estimate, the figure provides a useful estimate of childhood JE
incidence in Cambodia.

       Many challenges were confronted in the planning and implementation of the surveillance system.
In the following section, we outline these challenges and the responses made.

Challenges and responses with system development
Determination of case definition


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            Publication: Bulletin of the World Health Organization; Type: Lessons from the Field
                                     Article DOI: 10.2471/BLT.08.052951
Challenge
The WHO standards for surveillance of vaccine-preventable diseases do not currently include a case
definition for meningoencephalitis, although there are separate standards for bacterial meningitis and for
acute encephalitis syndrome/JE.8

Response
The clinical case definition that had been developed when syndromic ME surveillance was established in
Cambodia in 2005 was “a person with acute onset of fever ( 38 °C) and at least one of the following:
neck stiffness, altered consciousness, other meningeal sign”. This case definition more closely resembles
the WHO-recommended case definition for bacterial meningitis than acute encephalitis.8 However,
because the definition was considered to be sufficiently broad to include most presentations of
encephalitis, and clinicians were already familiar with the definition, it was maintained when JE sentinel
surveillance was incorporated in 2006.

Collection and testing of clinical samples

Challenge
Collection of cerebrospinal fluid – the key biological sample required for ME surveillance – is often a
challenge. Health systems in developing countries are not always equipped to routinely conduct lumbar
punctures, staff have not always been trained to conduct them and hesitancy may occur among clinicians
as well as family members because of perceived risks. The prioritization for use of a (potentially limited)
cerebrospinal fluid sample must also be clearly defined. The first priority for all specimens must be to
guide the immediate management and treatment of the patient. Logistics may also be a challenge. Some
diagnostic tests cannot be conducted in the local hospital laboratory and samples need to be transported.
Requirements for storage and transport may differ when different types of diagnostic tests are conducted.
Good coordination of clinicians, laboratory technicians and others who may handle the specimens is
required.

Response
In addition to standard operating procedures for specimen collection and management, which included a
schema for appropriate laboratory testing of specimens, ME case management guidelines and associated
training programmes were developed as a complementary strategy to surveillance capacity-building.
Indicators for assessing effective functioning of the surveillance system were defined and monitored.

Managing the limitations

Challenge




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            Publication: Bulletin of the World Health Organization; Type: Lessons from the Field
                                     Article DOI: 10.2471/BLT.08.052951
Underestimation of population incidence of disease attributable to specific etiologies may occur as a
result of limitations of currently available diagnostic testing methodologies. Timing of specimen
collection or prior use of antibiotics can affect the likelihood of a positive result. In addition, different
testing methodologies used (e.g. ELISA for JE diagnosis, or bacterial culture, polymerase chain reaction
or latex agglutination antigen tests for diagnosis of causes of bacterial meningitis) have different
sensitivities and specificities.

          There are also challenges with relying on sentinel surveillance to provide data to determine the
national picture of disease burden. In most Asian countries, laboratory testing of every ME patient
nationwide is not feasible. Hence, the accepted model is sentinel surveillance, with testing of samples
from patients at selected sites only. If sentinel sites are not truly representative, biases in disease burden
estimates occur. For example, if there is less access to hospital facilities for rural rather than urban
populations, then JE, a predominantly rural disease, may be under-represented.

          To estimate national incidences of particular vaccine-preventable CNS diseases, accurate
syndromic ME data are also needed. Under-reporting may occur due to multiple factors. For example,
individuals who die before presentation or do not access hospital facilities will not be included. Lack of
reporting from private-sector health services may also affect results.

Response
Systems to ensure quality of laboratory data were implemented, including a laboratory quality assurance
programme, and individual strategies such as encouraging collection of convalescent serum samples for
JE diagnostic testing. The need for careful interpretation of laboratory data was reinforced, ensuring it
was understood that the percentage of cases due to a particular viral or bacterial etiology could not
necessarily be directly compared based on laboratory results.

          Sentinel sites were selected after assessment visits and were carefully chosen from diverse
geographical areas, also taking into account other factors including capacity of the hospital to collect and
transport specimens. Monitoring of quality of data collection was undertaken during routine supervision
visits.

Discussion
Common causes of ME in Asia – JE, Hib and pneumococcal disease – are all vaccine preventable. With
Hib and pneumococcal disease, the impact of immunization is not just on CNS disease but on respiratory
and other invasive disease. These vaccines could therefore significantly reduce death and disability
among children. Data from the recently established sentinel ME surveillance system and more substantial




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           Publication: Bulletin of the World Health Organization; Type: Lessons from the Field
                                    Article DOI: 10.2471/BLT.08.052951
data from the region, and globally, suggest that 50% or more CNS infections in children in Cambodia
could be prevented through vaccination.

       There is a risk that a focus on individual neurological diseases may result in the emergence of a
wide variety of vertical laboratory testing and reporting systems that do not coordinate with national
health information systems, leading to fragmentation and inefficiencies in data collection and reporting.
This is the single most important lesson learned from the development of other vaccine-preventable
disease surveillance systems such as acute flaccid paralysis, measles and tetanus. Surveillance systems are
often de-linked in terms of planning, financing and data collection and analysis, resulting in widespread
inefficiencies and duplication of scarce financial and human resources.

       In relation to feasibility of integration of meningitis and encephalitis surveillance, it is crucial to
consider that we are dealing with one syndrome and one specimen collection procedure. In addition, the
overall operating system – consisting of the patient, the clinician, the surveillance forms, the on-site
laboratory testing, the transport system and the reference laboratory structure – remains constant. Based
on experience from Cambodia, Table 1 summarizes the rationale for integration of ME surveillance,
Fig. 1 provides an overview of an integrated ME surveillance structure and Box 1 summarizes the lessons
learned.

       Integrated ME surveillance is in line with WHO’s newly released strategy for vaccine-preventable
disease surveillance, the Global Framework for Immunization Monitoring and Surveillance.10,11 Four of
the seven goals of the framework include linking epidemiological and laboratory surveillance, building
surveillance capacity at the country level for disease burden estimates and impact monitoring, expanding
laboratory networks for viral and bacterial diseases and, finally, linking with other surveillance and
monitoring systems for early detection and response to emerging infections. Integration of meningitis and
encephalitis surveillance has the potential to successfully address these goals.

Conclusion
As demonstrated by this case study from Cambodia, an integrated ME surveillance system in Asia has the
potential to better define the population incidence and proportion of infectious CNS disease in children
that is vaccine-preventable. Public health priorities in the country, availability of viral and bacterial
diagnostics, and local disease patterns may all determine the appropriateness of this approach. However,
integrated surveillance has the potential to enhance the capability of public health managers to provide
more credible and integrated information to policy-makers about the potential role of immunization in
reducing childhood CNS infection-related death and disability. Additionally, it would provide a platform
for surveillance and investigation of any new or emerging CNS-related infections, monitor the impact of



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              Publication: Bulletin of the World Health Organization; Type: Lessons from the Field
                                       Article DOI: 10.2471/BLT.08.052951
    new vaccine programmes and streamline information and reporting in resource-poor public health
    systems in developing countries. 

    Acknowledgements
    We thank the laboratory staff at the National Institute of Public Health and at hospital sentinel sites, the
    various clinicians, communicable disease control staff, and national immunization programme staff and
    managers, who have supported the development of the surveillance system in Cambodia. We would also
    like to thank the following PATH staff: Kathy Neuzil, acting director of JE project, for her review of the
    manuscript; Jodi Udd for editing support; and the staff in the Cambodia office.
    Funding: The work undertaken was funded by PATH’s Japanese Encephalitis Project, supported by the
    Bill & Melinda Gates Foundation. As a partnership programme, the Ministry of Health in Cambodia has
    full control of primary data.
    Competing interests: None declared.

    References
<jrn>1. Tsai TF. New initiatives for the control of Japanese encephalitis by vaccination: minutes of a
       WHO/CVI meeting, Bangkok, Thailand, 13-15 October 1998. Vaccine 2000;18 Suppl 2;1-25.
       PMID:10821969 doi:10.1016/S0264-410X(00)00037-2</jrn>
<jrn>2. Wang CH, Lin TY. Invasive Haemophilus influenzae diseases and purulent meningitis in
       Taiwan. J Formos Med Assoc 1996;95:599-604. PMID:8870429</jrn>
<jrn>3. Solomon T, Dung NM, Kneen R, Gainsborough M, Vaughn DW, Khanh VT. Japanese
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<jrn>4. Chotpitayasunondh T. Bacterial meningitis in children: etiology and clinical features, an 11-
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<jrn>5. Beasley DW, Lewthwaite P, Solomon T. Current use and development of vaccines for
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<jrn>6. Chhour YM, Ruble G, Hong R, Minn K, Kdan Y, Sok T, et al. Hospital-based diagnosis of
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<jrn>7. Srey VH, Sadones H, Ong S, Mam M, Yim C, Sor S, et al. Etiology of encephalitis syndrome
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<bok>8. WHO-recommended standards for surveillance of selected vaccine-preventable diseases.
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             Publication: Bulletin of the World Health Organization; Type: Lessons from the Field
                                      Article DOI: 10.2471/BLT.08.052951
<unknown>11. Global framework for immunization monitoring and surveillance. Geneva: World
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   Table 1. Rationale for integrated meningoencephalitis surveillance in Asia

    Rationale                                                         Comments
    Increasing case detection           In patients with CNS infections, there is a clear overlap between
    through a syndromic                 those that meet the case definition for “acute encephalitis syndrome”
    approach to overlapping             and for “bacterial meningitis”. Initial assignment of patients for
    clinical syndromes                  reporting through one particular system could result in incomplete
                                        case detection and an inaccurate representation of disease burden.
    Consistency with routine            The approach to investigation of a patient with suspected meningitis
    clinical management                 or encephalitis is the same – a lumbar puncture is routinely
    procedures                          recommended for collection of cerebrospinal fluid to assist diagnosis
                                        and guide treatment. Samples can be collected at the same time for
                                        treatment and public health purposes.
    Streamlining of                     Low-income countries frequently lack operational expenses for basic
    surveillance systems                health services, so the best use of resources is essential and an
                                        integrated system can help reduce programmatic duplication and
                                        streamline staff time. It also provides an operational system for
                                        surveillance for other diseases that may become public health
                                        priorities (e.g. mumps and enterovirus infection) and for newly
                                        emerging infectious neurological diseases.
    Facilitation of decision-           Integrated surveillance has the potential to provide disease burden
    making and evaluation of            data on several vaccine-preventable CNS diseases of public health
    new vaccine introduction            importance in a comprehensive and coordinated way. The same
    programmes                          system can be used for both decision-making (burden of disease)
                                        and evaluation of vaccine introduction programmes.
    Highlighting the impact of          Meningoencephalitis surveillance with collection of clinical outcome
    childhood neurological              data will demonstrate the impact of CNS infections and reinforce the
    disease                             need to strengthen capacity for good clinical case management to
                                        improve outcomes. It will also focus attention on the need to support
                                        children disabled from disease, consistent with the 2005 World
                                        Health Assembly resolution to improve outcomes for persons with
                                        disabilities.9

   CNS, central nervous system.
   Fig. 1. Overview of an integrated meningoencephalitis surveillance system
   CNS, central nervous system; ME, meningoencephalitis.
   Box 1. Lessons learned
   Sentinel surveillance systems, when linked to syndromic reporting systems, can characterize
   the epidemiology of meningoencephalitis and identify the proportion of hospital-based
   neurological infection in children that is vaccine preventable.




                                                  Page 9 of 10
        Publication: Bulletin of the World Health Organization; Type: Lessons from the Field
                                 Article DOI: 10.2471/BLT.08.052951
Integrated systems enable consistency in data collection, analysis and information
dissemination and enhance the capacity of public health managers to provide more credible and
integrated information to policy-makers.
This will assist decision-making about the potential role of immunization in reducing the
incidence of childhood neurological infections.




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